Race/Ethnicity, Educational Attainment, and Pregnancy Complications in New York City Women with Pre-existing Diabetes

BACKGROUND: More women are entering pregnancy with pre-existing diabetes. Disease severity, glycaemic control, and predictors of pregnancy complications may differ by race/ethnicity or educational attainment, leading to differences in adverse pregnancy outcomes. METHODS: We used linked New York City hospital record and birth certificate data for 6291 singleton births among women with pre-existing diabetes between 1995 and 2003. We defined maternal race/ethnicity as non-Hispanic white, non-Hispanic black, Hispanic, South Asian, and East Asian, and education level as <12, 12, and >12 years. Our outcomes were pre-eclampsia, preterm birth (PTB) (<37 weeks gestation and categorised as spontaneous or medically indicated), as well as small-for-gestational age (SGA) and large-for-gestational age (LGA). Using multivariable binomial regression, we estimated the risk ratios for pre-eclampsia, SGA, and LGA. We used multivariable multinomial regression to estimate odds ratios (OR) for PTB. RESULTS: Compared with non-Hispanic white women with pre-existing diabetes, non-Hispanic black and Hispanic women with pre-existing diabetes had a 1.50-fold increased risk of pre-eclampsia compared with non-Hispanic whites with pre-existing diabetes, after full adjustment. Non-Hispanic black and Hispanic women with pre-existing diabetes had adjusted ORs of 1.72 [adj. 95% confidence interval (CI) 1.38, 2.15] and 1.65 [adj.95% CI 1.32, 2.05], respectively, for medically indicated PTB. South Asian women with pre-existing diabetes had the highest risk for having an SGA infant [adj. OR: 2.29; adj. 95% CI 1.73, 3.03]. East Asian ethnicity was not associated with these pregnancy complications. CONCLUSIONS: Non-Hispanic black, Hispanic, and South Asian women with pre-existing diabetes may benefit from targeted interventions to improve pregnancy outcomes.